Update: The FAA tells CBS News the computer outage has forced a halt to departures at airports in Las Vegas, Phoenix, Salt Lake City and at other airports in the region as well.

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The FAA says computer issues are forcing a ground stop at Los Angeles International Airport.  

Airport spokeswoman Nancy Castles said Wednesday afternoon that the Federal Aviation Administration had put a "ground stop" on departures. Arrivals were still being accepted.

Castles wasn't sure what caused the problem. An FAA spokesman did not immediately respond to a request for comment.

Los Angeles International is the nation's third-busiest airport. 

The airport's website is reporting departure delays of 45 minutes to an hour. 

-- The Associated Press contributed to this report.